The present invention relates to an apparatus for cutting and removing a package material from a packaged object, and more particularly to an apparatus for cutting and removing a package material from a cylindrical packaged object.
Ends to be attached to open-top food cans which will be filled with beer, beverage, or the like are stacked after they have been manufactured, then packaged and sent to a canning process. In the canning process, the package is removed from an end stack, and the ends are supplied one at a time to an open-top can which has been filled with a content and positioned for end seaming. Then, the end is placed on the open top of the can and attached thereto by seaming.
Japanese Laid-Open Patent Publication No. 58-41030 discloses an apparatus for removing a package sheet from a packaged cylindrical object such as a stack of can ends. As shown in FIGS. 24(a) and 24(b) of the accompanying drawings, the disclosed apparatus includes a pair of lower rollers 41, 42 for receiving a packaged cylindrical object 43 wrapped by a package paper 44. The lower rollers 41, 42 are rotated in contact with the object 43 to stretch the package paper 44, thereby forming a slackened portion between the rollers 41, 42. The slackened portion of the package paper 44 is then longitudinally cut by a cutter 45 [see FIG. 24(a)]. Thereafter, a pair of upper rollers 47, 48 held in contact with the object 44 is rotated to grip the package paper 44 therebetween and remove the package paper 44 upwardly [see FIG. 24(b)].
Another known package paper remover is disclosed in Japanese Laid-Open Patent Publication No. 56-41498. According to the disclosed package paper remover, as shown in FIGS. 25(a) through 25(d) of the accompanying drawings, a package paper 54 wrapping a cylindrical object 53 on a v-shaped receiver 56 is gripped by a pair of grippers 51, 52, and the packaged object 53 is lifted off the receiver 56 to make a stretched portion of the package paper 54. A cutter 55 is operated to cut the stretched portion of the package paper 54 [FIG. 25(b)]. Then, the grippers 51, 52 are opened to drop the object 53 onto the receiver 56 [FIG. 25(c)], after which the packaged object 53 is placed on a pair of rollers 57, 58. The rollers 57, 58 are rotated in opposite directions to draw the package paper 54 therebetween and remove the same from the object 53 [FIG. 25(d)].
In both of the above known package removing apparatus, the package paper is pulled to make a slackened or stretched portion, cut, and then removed while the packaged object is being stopped. Where package papers are to be successively removed from a number of packaged objects, a next packaged object must be kept in a standby condition for a long period of time while the package paper is being removed from one packaged object. Therefore, the earlier package removers have a limited capacity when removing package papers from a succession of packaged objects.
With the package removing apparatus disclosed in the former publication, since the lower portion of the package paper 44 is slackened by frictional engagement with the rollers 41, 42, it may not successfully be slackened due to roller slippage or the like, and hence may not successfully be cut by the cutter 45. Another problem is that inasmuch as the cutter 45 approaches the packaged object 43 in order to cut the package paper 44, the cutting edge of the cutter 45 may directly contact the packaged object 43, thus damaging the object 43 or the cutter 45 or both.
According to the package remover disclosed in the latter publication, the packaged object 53 is lifted off the receiver 56 and the cutter 55 is advanced toward the stretched portion of the package paper 54 before the package paper 54 is cut. The packaged object 53 must therefore be lifted or suspended horizontally for proper positional relationship to the cutter 55. Because the grippers 51, 52 are associated with a lifting device, the entire package removing apparatus is complex in structure and highly costly. The cutting edge of the cutter 55 may also directly contact the packaged object 53, thus damaging the object 53 or the cutter 55 or both.